In recent years, many databases for accumulating various kinds of data have been established, with development of the information society.
For example, there are established many databases such as a database for accumulating books in libraries and papers of research institutions, a database for accumulating scenery images in association with position information based on maps, a database for accumulating patent publications, a database for accumulating weather data, and the like. In addition, most of such databases allow general users to search for or refer to data, and many users use such databases.
In addition, in recent years, with development of information analysis technologies, research on pattern recognition technologies has been advanced in which it is possible to identify a type of data by extracting a feature amount from the data. Examples of such pattern recognition technologies include a sound identification technology for identifying types of sounds included in sound data, an optical character recognition technology for identifying characters in image data, a face authentication technology for identifying faces of individuals in image data, and the like.
A specific example of the sound identification technology for identifying types of sounds included in sound data is a technology described in Non-Patent Literature 1 listed below. By using the technology described in Non-Patent Literature 1, it is possible to recognize types of sounds and establish databases in which sounds are accumulated by the type.